This invention relates to hair rollers and, more particularly, to an improved form of cylindrically shaped hair roller which may be stored flat.
The use of rollers for the styling and setting of hair is well known. In one arrangement, a hair roller body which is generally cylindrically shaped is provided and a person's hair is wound about and secured to the roller body. The hair thus formed on the roller body can be warmed to enhance setting. Alternatively, the hair remains wound about the curling body for an extended period of time to achieve setting under ambient air conditions.
The use of hair rollers is facilitated when the cylindrically shaped roller body is substantially resistant to bending and buckling. It is also desirable for purposes of packaging by the manufacturer and storage by the user to provide a roller of this type which can be stored in a substantially flat configuration.
In a copending U.S. patent application Ser. No. 741,611 which is filed concurrently herewith and which is assigned to the assignee of this invention, a hair roller of the type described is disclosed and is formed of two, flexible, generally planar shaped roller members which are mechanically intercoupled by a hinging means. In one arrangement, both longitudinally extending edges of one roller member are hinge coupled to a surface of the other roller member. In another disclosed arrangement, one edge of each roller member is hinge coupled to a surface of the other roller member. In another arrangement, the roller members are hinge coupled along their edges.
These hair roller arrangements are adapted to be stored in a generally flat configuration and to be expanded into a body having a generally cylindrically shaped configuration. While the body is generally cylindrically shaped, it is found that, at times, the body departs from a circular cross section of the generally cylindrical configuration. This departure occurs along the circumference in the hinged area. In hinge coupling between an edge and a surface of opposite members, an overlapping and doupling up of the circumferential thickness of the body wall exists for a portion of the circumference and this doubling up introduces a stiffness in the body which resists conformity to the desired circular cross section. In the case where edge segments of each member are hinged, a discontinuity in the circular cross sectional configuration exists at the hinge joint. Hair roller users prefer to use a circular cross sectional body and these departures from a circular cross section are therefore undesirable.
Accordingly, it is an object of this invention to provide an improved hair roller of the type described having first and second roller members which are hinged coupled and which exhibit a substantially circular cross sectional configuration.
Another object of the invention is to provide a hair roller of the type described having means for reducing departures of the hair roller from a circular arc in the area of a hinged coupling.